Preparation and optimization of silibinin-loaded chitosan-fucoidan hydrogel: an in vivo evaluation of skin protection against UVB

The objective of this study was to develop silibinin-loaded hydrogel for skin protection against UVB damage. Physical grafting was used to prepare hydrogel based on chitosan-fucoidan. Then, hydrogel properties, such as swelling, drug release rates, morphology, and structure, were evaluated to determine the optimum hydrogel for in vivo studies. In in vivo experiments, the silibinin permeability parameters were investigated through normal and UV-irradiated skin, anti-inflammatory property, and antioxidant effects after application of optimum hydrogel. The silibinin completely dispersed in the hydrogel, and FT-IR results showed that silibinin reacted with the chitosan and fucoidan and demonstrated a slow release pattern. The 50% and less than 70% of the drug-loaded on hydrogel were passed through normal and irradiated skin after 48 h, respectively. In vivo studies showed the effectiveness of optimized hydrogel in preventing the production of oxidative species and H 2 O 2 after UVB radiation. Histological studies have shown that silibinin-loaded optimized hydrogel can prevent the hyperkeratosis, acanthosis, and infiltration of neutrophils into the dermis by UVB. Optimized hydrogel effectively reduced the inflammation mediators interleukin-22 and TNF-α, which signify tissue destruction. Therefore, silibinin-loaded hydrogel can be introduced as an effective sun-protective product.